COVID-19: Saliva diagnosis cheaper, faster alternative to swab testing, say scientists

Team Udayavani, Aug 22, 2020, 1:31 PM IST

New Delhi: A low-cost saliva test that will enable people to collect their own samples with minimal discomfort, without invasive nasal or throat swabs, could well be the way forward to detect the novel coronavirus, say scientists.

Giving a thumbs up to the alternative testing technology that is yet to be introduced in India, scientists said it would deliver results faster and more accurately and also minimise the risk for healthcare workers collecting samples.

The saliva-based COVID-19 diagnosis offers an improvement over standard nasopharyngeal swab methods because people can collect their own samples with ease, simply spit into a sterile tube and mail it to a lab for processing.

“It is also unique because it does not require a separate nucleic acid (RNA) extraction step. This is significant because the extraction kits used for this step in other tests have been prone to shortages in the past,” A R Anand, senior associate professor at Chennai’s L&T Microbiology Research Centre, told PTI.

Noting that the ‘saliva direct’ test is easier to carry out, he said it needs only a few reagents and a real-time polymerase chain reaction (RT-PCR) machine.

Though saliva tests are yet to be approved in India for mass use, scientists such as Anand suggest the matter be explored further.

“A fast-tracked study should be conducted in an Indian setting comparing the saliva RT-PCR tests with the nasopharyngeal RT-PCR tests before large-scale implementation in our country,” Anand said.

An Indian Council of Medical Research (ICMR) scientist added that India is exploring the availability of kits and other aspects. “At present, no kit is approved in India,” he said on the condition of anonymity.

According to a recent study published in ICMR’s Indian Journal of Medical Research, gargled water samples may be another viable alternative to swabs for detecting COVID-19, enabling easy self-collection and removing the need for trained healthcare workers for sample collection.